It all started one night when i'm lying in bed, then i came up with the idea of going to school the next day and being random, that way i'd get some cheap laughs from people, and i'd also be able to mildly annoy my friends, which is nice.
So then, the next day, i went to school and told every single person i knew that 'I like pie!' Then apparently my friend got so annoyed he started hating pie, and we'd have ridiculous and illogical arguments about pie. Then for the sake of arguing i've made up multiple facts about pie, about how they are the center of the universe, about how they're the wisest things on earth, how they beat the crap outta pizza and etc. (It was like 2 years ago, but yes, we knew it was a joke, yes, we enjoyed the joke.)
Then because I've made up so many facts about pie, one of then being 'the study of pie is called pielogy' and 'he who studies pielogy shall be called a pielogist'. Then when i'm making an account once, I just decided. 'Mmmm, I'll call myself Pielogist!'
And that's my story of how i got my name.